The use of matte boxes are known for reducing unwanted lens flare caused by lights or the sun, or for holding suitable glass or plastic filters in front of the lens. A common type of camera rig with which a matte box is used comprises two mounting rods which are supported parallel and spaced apart from one another to extend in a longitudinal direction. A camera body is anchored onto the rods at a first position thereon to be directed forwardly in the longitudinal direction for capturing images. Forwardly of the camera body along the rods, there is typically supported various accessories including for example an auxiliary lens, a lens adapter, or the matte box.
U.S. Pat. Nos. 5,708,902 by Navarro and 5,349,411 by Beauviala disclose examples of matte boxes supported on a pair of mounting rods of a camera rig as described above. In each instance there is provided a matte frame having a central lens opening therein arranged to be aligned with the lens of the camera such that filters which are supported to span the lens opening of the matte frame are positioned across the lens of the camera. Each of the assemblies further comprises a rail mount for fixed mounting onto the mounting rails of the camera rig. A support frame fixed to the rail mount is positioned towards one side only of the lens of the camera for supporting a hinge which pivotally couples the matte frame to the support frame for pivotal movement between an in-use position spanning the lens of the camera and an out-of-use position in which the camera lens is substantially unobstructed by the matte frame. In each instance the matte frame is unsupported at the opposing side from the hinges. Accordingly the matte frame is not supported in a stable manner and minor relative movements of the filters supported by the matte frame relative to the lens may cause distortions in the image being captured. Due to the support frame and hinges only supporting the matte frame on one side of the lens, the hinges are designed to be rather large and cumbersome as they are required to have sufficient clamping force to support the matte frame from only one side thereof.